English style decimal marks with a European keyboard layout

Suppose you live in Europe where they separate numbers with commas instead of periods.

Written:
Six thousand eight hundred and forty three and two tenthsEnglish/American:
6,843.2European
6 843,2

Suppose you also have a European keyboard and use a European keyboard layout but the stupid comma in the numpad drives you mad.

Simple fix
Open (or create) ~/.Xmodmap
Add the line “keycode 91 = KP_Delete KP_Decimal” and save
Run the command “xmodmap ~/.Xmodmap”
Test that it worked
Open ~/.xinitrc
Add the line “xmodmap ~/.Xmodmap” and save to make the change permanent.